System of regulated air supply for liquid-fuel furnaces



1929-- I B. NOLAND 1,713,111

SYSTEM OF REGULATED AIR SUPPLY FOR LIQUID FUEL FURNACES Filed Feb.,6, 1923 2 Sheets-Shet '1 anomto z .Barzbn E Noland flbtomeq 1 May 14, 1929. B. H. NOLAND SYSTEM OF REGULATED AIR SUPPLY FOR LIQUID FUEL FURNACES 2 She ets-Sheet 2 Filed Feb. 6, 1923 awuentoz Barion JZ/Volarzd 4 W Patented May 14, 1929.

PATENT OFFICE.

BARTON H. NOLAN D, OF BROOKLYN, NEW YORK.

SYSTEM OF REGULATED AIR SUPPLY FOR LIQUID-FUEL FURNACES.

Application filed February 6, 1923. Serial No. 617,422.

This invention relates to an improved system of regulated air supply for liquid fuel furnaces employing one or a number of burners, and my improvement has particular reference to means whereby pressure of air, variable according to the pressure of liquid fuel supplied to the burners, is proportioned to the combustion needs of the respective burners.

In the present practice of certain liquid fuel burning furnaces, it is customary to provide individually adjustable air supply means for the burners. Since furnaces including a number of burners usually have an air admission means which is common to the burners, and pressure applied to the control means for the individual burners varies because the control means are located differently with respect to the common admission means, it is now necessary that the individual control means be subject to separate manual operation for proportioning the flow of air to suit the combustion needs of the several burners.

In another patent application, Serial No. 617,421, filed concurrently herewith, I have described a system of automatic control for the supply of air governed by the pressure of liquid fuel flowing to a burner. It is by similar means that I purpose, in the present application, to govern, by the pressure of liquid fuel, the proper proportionate supply of air flowing to individual burners of a furnace having a plurality of burners supplied with air from a common surce.

This requires that the individual air control means for each of the burners be .accorded a determined setting whereby each individual air control means is rendered capable of admitting to its burner a proportional air supply.

In order to determine the fuel and air requirements a gas analysis is taken of the consumed mixture provided for each individual burner and the air control means is then set in accordance with the ascertained efficient combustion result secured under a given pressure of liquid fuel and the supply of air as governed by that pressure.

In consequence, the proportion of the air supplied to the respective burners will be maintained under varying pressures of liquid fuel, and without necessitating any individual or general, manual or other adjustment of the air control means for the burners.

Other features and advantages of my invention will hereinafter appear.

In the drawings:

Figure 1 is a front view of a Scotch marine boiler with three furnaces, each having a separate liquid fuel burner, and showing means for supplying air thereto, common to all the burners thereof; also showing pressure means for the supply of air, and means whereby the pressure of liquid fuel supplied to the burners controls the volume of air which is supplied to the furnace.

Fig. 2 is a side elevation of a furnace, of another type, which is provided with one or a number of burners, having means for suplying air to the furnace, and means wherey the pressure of liquid fuel supplied to the burner is enabled to control the volume of air which is supplied by said burners to the furnace, and

Fig. 3 is a section on the line 3-3 of Fig. 1.

In first describing my improvement as applied to forced draft furnaces such as in the example of Figs. 1 and 3, let 1 indicate the boiler, which is shown as provided with the furnaces 2,' 3 and 4. The uptake 5 is broken away, thereby representing it as also serving an adjacent boiler. 6 indicates an air supply duct, which may be common to boiler 1 and an adjacent boiler (not shown), and 7 indicates a pipe which is in communication with duct 6 as at 8, the pipe 7 serving to conveyair under pressure to duct 6, from a suitable source of pressure supply, as a pump 9.

Air under pressure is supplied to the boiler 1 through the opening 10 in duct 6, which communicates with the side passages 11, 11, which connect with the furnaces 2, 3 and 4.

The furnaces are here represented as equipped with Todd burners, and air control means in the form of a slidable cone 12.

These or other air control means are usually adj ustable, being. manually operable to vary the quantity of air supplied to each furnace, to produce with the liquid fuel a proper combustible mixture. But by the use of my automatic proportioning means for liquid fuel and air, comprised in my concurrent application, already referred to, manual operationof the air control means may be dispensed with, the air supply to the burners being regulated by and according to the variable pressure under which liquid fuel passes to the burners. This necessitates the proper setting of the air control means for the respective burners, such as the cones 12. This proper setting of the air control means is determined after analyzing the gases of combustion, and establishes a standard of air pressure for a given pressure of liquid fuel, and with this fixed relation between a given pressure of liquid fuel and a proportionate pressure of air, it follows that the ratio of the two elements can be maintained automatically by merely varying the pressure of the liquid fuel supply.

In the embodiment of the invention illus trated in Fig. 1, 1 provide an expansible air container 13, the movable element of which is connected by a cable 14 with a suitable operating arm on a valve 15 which controls the supply of steam to an engine 9. This engine drives a suitable pump or fan as shown which maintains a pressure of air in the supply pipe 7.

The movable element of-the expansible air container is connected with a balance arm having a slidable weight 16 thereon which can be shifted toward or away from the pivot- 16" on which the arm 16 is balanced. The

weight 16"-is shifted in response to variations.

of pressure of the liquid fuel by the pressure actuated element 18, which is connected by pipe 17 with the common oil supply pipe 17 having branches 2*, 3 and 4.

I have indicated, at 19, a pipe which connects the air duct 6 and air container 13, to admit air to said container and thereby aid in resisting the descent by gravity of the movable element of the air container as the air pressure increases in duct 6.

In the other type of boiler shown in Fig. 2, represented as operating under natural draft, a furnace front is indicated at 20 as having an air control valve 21. This valve is adapted to be set to provide a certain air opening in accordance with the position of the damper 22 in the flue 23 which leads to the stack, so that the induced draft will cause a certain volume of air to flow into the furnace, and the required corresponding quantity of liquid fuel will be supplied to burner 21 by the usual oil pressure regulating means.

The oil pressure actuated device 25, acting through balancing means 26 and the expansible air container 27, aetuates a valve 28 which controls a hydraulic motor 29. The piston rod 30 of the motor engages a lever 31, fulcrumed at 32, which operates the damper 22 through a link 33. Hence the damper 22 is actuated by the movement of the air container 27, as a direct result of the varying pressure of liquid fuel, aided by the varying pressure in the furnace, which is in communication with the air container by pipe 34. As will be apparent from the foregoing description, a particular feature of the present invention consists in the individual adjustments to which the respective air admission means 12 are setin differentiating the common pressure supply from duct 6 to the needs of the differentfurnaces. The air admission means 12 above referred to each include a member having ports whose inlet areas can be manually varied. The structure includes a substantially cylindrical shell having a number of ports therein. A sleeve fitted over the cylindrical member is provided with corresponding ports. By shifting the sleeve relatively to the shell, the inlet areaof the ports may be readily varied as will be understood.

Variations within the spirit and Scope of my invention are equally comprehended by the foregoing disclosure.

1 claim:

1. The combination with a plurality of burners of a common pipe for delivering fuel thereto and a common pipe for delivering air thereto, individually adjustable air control devices for each of said burners adapted to be manipulated manually to suit the combustion requirements of the respective burners and means controlled jointly by the common fuel supply and the common air supply for maintaining a substantially predetermined ratio between the supply of fuel and of air.

2. The combination with a plurality of burners of a common pipe for delivering fuel thereto and a common pipe for delivering air thereto, a blower for supplying air under pressure to said air pipe, individually adjustable air control devices for each of said burners adapted to be manually manipulated to suit the combustion requirements of the respective burners and means controlled by the ratio of the fuel supply to the air supply for regulating the operation of the blower to maintain a substantially predetermined ratio between the supply of fuel and of air.

Signed at the borough of Manhattan, in the city, county and State of New York, this 25th day of January, A. l). 1923.

BARTON ll. NOLAND. 

